# Cannot read/write to AXI-Lite registers \[MATLAB IP\]

**URL:** <https://discuss.pynq.io/t/cannot-read-write-to-axi-lite-registers-matlab-ip/6927>\
**Category:** Support\
**Created:** [April 15, 2024, 10:14am UTC](https://discuss.pynq.io/t/cannot-read-write-to-axi-lite-registers-matlab-ip/6927 "2024-04-15T10:14:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dewasser](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dewasser](https://discuss.pynq.io/u/dewasser)\
**Post date:** [April 15, 2024, 10:14am UTC](https://discuss.pynq.io/t/cannot-read-write-to-axi-lite-registers-matlab-ip/6927/1 "2024-04-15T10:14:25Z")

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PYNQ version: 3.0.0, board Kria KV260

Hello, I am using a Sobel IP generated from MATLAB’s HDL Vision Toolbox. I have some issues accessing the AXI-Lite registers for enabling the core and setting video parameters. Example below:

 ![pynqmatlab](https://us1.discourse-cdn.com/flex019/uploads/pynq1/original/2X/e/ec2a0acbba85e6a9f0cb1fbc34f13c224eb07df6.png)

As you can see I am unable to set the registers by writing to them. The issue seems similar to that encountered [here](https://discuss.pynq.io/t/matlab-generated-ip-core-data-type-error/2417) but that solution did not work for me.

I also tried writing the registers with devmem2 instead to rule out PYNQ incompatability but that was also unsuccesful. However, I noticed every other register gave me Bus error which seems strange to me. Otherwise the results were identical

Has anyone had similar issues with using Matlab IP’s? I also made a post on the MATLAB board since I suspect the issue might not be strictly related to PYNQ

Edit: I was able to read from them after enabling readback in the matlab workflow advisor. I still don’t get any frame output from the IP however but this is a separate issue

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**Author:** ![cathalmccabe](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/cathalmccabe/32/3348_2.png) [@cathalmccabe](https://discuss.pynq.io/u/cathalmccabe)\
**Post date:** [May 8, 2024, 2:27pm UTC](https://discuss.pynq.io/t/cannot-read-write-to-axi-lite-registers-matlab-ip/6927/2 "2024-05-08T14:27:31Z")

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> [@dewasser](#):
>
> I was able to read from them after enabling readback in the matlab workflow advisor. I still don’t get any frame output from the IP however but this is a separate issue

Do you still have an issue (other than frame output)? It seems enabling readback resolved your question?

Cathal